Citing lawsuits, police reports and other official documents, the news site said the company, Massage Envy, and its franchisees had mishandled or ignored many of more than 180 cases. NBC News has not confirmed all of the allegations.

In a statement Sunday, Massage Envy — which has more than 1,100 franchises in 49 states, according to the company's website — said the incidents described in the report were "heartbreaking for us and for the franchisees that operate Massage Envy locations."

Adam Horowitz, a lawyer who has worked on two dozen cases against Massage Envy, said the actual number of assaults is likely considerably higher.

Ex-USA Gymnastics Doctor Pleads Guilty to Sexual Assault Charges

Larry Nassar, a former doctor for USA Gymnastics and Michigan State University, pleaded guilty to multiple charges of sexual assault. He faces a sentence of at least 25 years in prison.